Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the full burden and does it well: exact-match-only behavior, list-entry response rather than risk score, snapshot publication date on every answer, no API key/account, and a concrete pricing/payment mechanism. These are precisely the traits an agent needs before calling.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Six compact sentences, each carrying a distinct fact — coverage, response shape, matching mode, provenance, auth, cost. No repetition and no filler.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a single-parameter, no-output-schema tool with no annotations, the description covers what it does, how it matches, what it returns, data freshness, auth requirements, and payment. Nothing an agent needs to call it correctly is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% and the single parameter is fully documented there, so the schema does the heavy lifting. The description adds currency breadth ('16 currencies including Ethereum, Bitcoin, Tron, USDT'), which is useful context but doesn't extend parameter semantics beyond the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ('Checks one crypto address against the OFAC SDN list'), names the source (US Treasury), and scopes the answer format ('a hit returns the actual list entry, not a risk score'). No sibling tool overlaps with sanctions screening, and the description makes its distinct purpose unmistakable.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Clearly frames the screening context and what a hit means, and states 'Exact matching only, never fuzzy,' which tells the agent when results will and won't appear. It doesn't explicitly name a contrasting sibling, but no sibling could be confused with OFAC screening, so an exclusion is unnecessary.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.